- Four-component radical-dual-difunctionalization (RDD) and decarbonylative alkylative peroxidation of two different alkenes with aliphatic aldehydes and TBHP
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From difunctionalization of a single alkene to radical-dual-difunctionalization of two different alkenes! Abundant aliphatic aldehydes were readily decarbonylated into alkyl radicals for the cascade construction of C(sp3)-C(sp3), C(sp3)-C(sp3) and C(sp3)-O bonds via double radical addition and radical-radical coupling, following the intrinsic nucleophilic/electrophilic reactivity of both the radicals and alkenes.
- Liu, Ren-Xiang,Zhang, Feng,Peng, Yong,Yang, Luo
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p. 12080 - 12083
(2019/10/14)
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- Preparation method of aromatic ketone compound with different functional groups substituted at beta and delta positions
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The invention discloses a preparation method of an aromatic ketone compound with different functional groups substituted at beta and delta positions. The preparation method includes: adopting aromatic aldehyde, electron-deficient olefin, a styrene derivative and tert-butyl peroxide as reaction substrates, catalyzing with transition metal to subject the reaction substrates to free radical cascade reaction so as to generate peroxide, and adding alkali into a reaction system to transfer the peroxide into the aromatic ketone compound with the different functional groups substituted at the beta and delta positions. According to the preparation method, the tert-butyl peroxide is adopted as a free radical initiator and an oxidizing agent, the aromatic aldehyde is transferred into an acyl free radical, the acyl free radical is then subjected to addition with the electron-deficient olefin (such as acrylics, acrylonitrile and acrylamide compounds) and the styrene derivative successively and then coupled with the tert-butyl peroxide to obtain the corresponding peroxide, the newly generated peroxide is subjected to Kornblum-DeLaMare rearrangement under an action of the alkali, and then the aromatic ketone compound with the different functional groups substituted at the beta and delta positions is obtained through one pot reaction. A reaction temperature is in a range of 25-150 DEG C, and the reaction lasts for 0.1-72 hours. Compared with methods in the prior art, the preparation method of the aromatic ketone compound with the different functional groups substituted at the beta and delta positions has the advantages that deficiencies of complexity in steps and poor selectivity of traditional methods for synthesizing the aromatic ketone compound with the different functional groups substituted at the beta and delta positions are overcome; in one reaction, bifunctionalization and cross-coupling of two olefins are realized, three new chemical bonds are constructed and introduced into two functional group aromatic ketone products; raw materials are easy to obtain; the preparation method is also simple to operate, safer, more economic and more efficient and insensitive to air, water and light and high in yield; prepared products are easy to separate and purify and have excellent application prospect.
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- Four-Component Radical Dual Difunctionalization (RDD) of Two Different Alkenes with Aldehydes and tert-Butyl Hydroperoxide (TBHP): An Easy Access to β,δ-Functionalized Ketones
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A convenient Fe-catalyzed four-component radical dual difunctionalization and ordered assembly of two alkenes with aromatic/aliphatic aldehydes and TBHP to provide chain elongated β,δ-functionalized ketones via a one-pot procedure has been developed. Alde
- Wu, Chuan-Shuo,Liu, Ren-Xiang,Ma, Da-You,Luo, Cui-Ping,Yang, Luo
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supporting information
p. 6117 - 6121
(2019/08/20)
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- Redox-Neutral Dual Functionalization of Electron-Deficient Alkenes
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Visible-light photoredox catalysis has been utilized in a new multicomponent reaction forming β-functionalized δ-diketones under mild conditions in an operationally convenient manner. Single-electron reduction of in situ generated carboxylic acid derivatives forms acyl radicals that react further via 1,2-acylalkylation of olefins in an intermolecular, three-components cascade reaction, giving valuable synthetic entities from readily available starting materials. A diverse set of substrates has been used, demonstrating robust methodology with broad substrate scope.
- Pettersson, Fredrik,Bergonzini, Giulia,Cassani, Carlo,Wallentin, Carl-Johan
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supporting information
p. 7444 - 7447
(2017/06/06)
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- 1,5-Diaryl-3,3-disubstituted-1,5-pentanedione - A synthon for 2,4,6-trisubstituted heterocycles
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2,4,6-Trisubstituted heterocycles are prepared by the functionalization of gem-disubstituents and keto functionalities in 1,5-diaryl-3,3-dimethoxycarbonyl- 1,5-pentane-dione (1) and 1,5-diaryl-3-cyano-3-ethoxycarbonyl-1,5-pentanedione (4).
- Padmavathi,Balaiah,Jagan Mohan Reddy,Padmaja
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p. 599 - 604
(2007/10/03)
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- Ligand-induced selectivity in the rhodium(II)-catalyzed reactions of α-diazo carbonyl compounds
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3-Allyl-2,5-diazopentanedione and 3-butenyl-2,5-diazopentanedione were allowed to react with a trace amount of a rhodium(II) catalyst in methylene chloride at room temperature. The major products isolated correspond to the internal trapping of a carbonyl ylide as well as intramolecular cyclopropanation. Changing the catalyst from Rh2(OAc)4 to Rh2(cap)4 to Rh2(tfa)4 caused a significant alteration in product distribution. A rather unusual and unexpected regiochemical crossover in the cycloaddition occurred when Rh2(tfa)4 was used and is most likely due to complexation of the metal with the dipole. A computational approach to rationalize the observed product distribution was carried out. The thermodynamic stabilities of cycloaddition transition states were approximated from the computationally derived strain energies of ground state molecules using traditional force-field techniques. Globally minimized ground state energies were obtained for all possible cycloaddition products, and final strain energies were calculated. In all cases studied, the lower energy isomer corresponded to the cycloadduct actually isolated. A study of the regiochemical aspects of the Rh(II)-catalyzed reaction of 1-diazo-3-(2-oxo-2-phenylethyl)hexane-2,5-dione was also carried out. Cyclization of the initially formed rhodium carbenoid occurred exclusively across the acetyl rather than the benzoyl group. The structure of the internal cycloadduct was assigned on the basis of a proton-detected multiple-bond heteronuclear multiple-quantum coherence experiment.
- Padwa, Albert,Austin, David J.,Hornbuckle, Susan F.
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